<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>Document</title>
	</head>
	<body>
		<script type="text/javascript">
			//设置函数参数的默认值
			//ES5方式
			// function fn(name,age) {
			// 	name = name || "tom";
			// 	age = age || 17;
			// 	console.log(name+","+age);
			}
			//ES5+类型检查
			// function fn2(name,age) {
			// 	name=(typeof name!='undefined'?name:'tom');
			// 	name=(y=typeof age!='undefined'?age:17);
			// 	console.log(name+","+age);
			// }
			
			//ES6方式
			// function fn3(name='tom',age=17){
			// 	console.log(name+","+age);
			// }
			
			// fn();
			// fn2();
			// fn3();
			
			//rest参数
			//ES5方式
			function join(){
				var str="";
				for(var i=0;i<arguments.length;i++){
					if(i==0){
						str=arguments[i];
					}else{
						str+="|"+arguments[i];
					}
				}
				return str;
			}
			console.log(join("hello","world"));
			
			//ES6
			function join2(...strs){
				var str="";
				for(var i=0;i<strs.length;i++){
					if(i==0){
						str=strs[i];
					}else{
						str+="|"+strs[i];
					}
				}
				return str;
			}
			console.log(join2("hello","world","你好","世界"));
		</script>
	</body>
</html>